Post 4" Lift Woes - Violent Braking & Rumbling

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kjandb
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Post 4" Lift Woes - Violent Braking & Rumbling

Post by kjandb »

Finally installed the BJ's 4" leaf lift. Love the new look and stance but now I've ran into two (possibly unrelated issues) I'm hoping someone can help with.

First, when I'm at 20-30mph and I let off the gas I'm getting a rumbling from underneath. Hard to tell where, but seems to be more towards the back end. Thought maybe u-joints were settling into the new post-lift angle or they needed replaced. Didn't find any play in the joints but noticed this play in the back t-case side:
I'm guessing this isn't good? I felt somewhat comfortable changing u-joints but I don't have a clue how to tackle this.

My second issue is the rig shakes violently when braking now. After extending the brake lines I bled them - and have since done it again to double check everything. I've also adjusted all 4 drums to make sure they're good. When they're up on jacks everything seems to be the same as they were prior to the lift. I don't think this is related to my first issue and I have to be missing something with my brakes - right?

Added a few more pics for reference - as I'm sure you can tell I'm new to jeeps and trying to learn. Not sure, but I believe the shackle angle isn't great but shouldn't be causing this. I read I needed to drive it and they would settle in better?? Hard to do with my current brakes.

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Ignore the fluids on the floor. I think that's normal? :D
'71 Wagoneer - 4" BJ's Leaf Lift - early 360 - Avocado Mist ???
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devildog80
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by devildog80 »

Nice looking rig.

Keep at it and you will get it figured out.

More will chime in that have more experience with this year :)
'81 CJ5 Base, 258 I6, MC2100, T176 4 spd, 300 TC, D30 Front NT, 3.31, 2-Piece AMC 20 rear NT, 3.31, 4" high arc spring lift
'84 Grand Wagoneer, 401 V8 (.030 over), MC2150 HA Comp, 727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT - WT 3.31, 4" high arc spring lift
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Stuka
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Stuka »

My first question is did you leave the spring bolts loose until it was on the ground on its own weight?

If you torque it while there is no weight on the suspension, you will basically cause it to give you way more lift than you should have. Your front spring hangers should only be that far back if the suspension is drooped. Not if it has weight on it. Now, if you DID leave everything loose until it was on the ground, it looks like those springs just have way more than 4" of lift. Thats much closer to 6" as it sits now. Which is has a good chance of causing u-joint angle issues. Though the rear would have better angles with a flanged rear output (see comments below).

Next, your wagoneer has what is called a ball and trunnion joint on the back of the transfercase. These do not handle lifts well at all. The rear output bearing has probably been bad for a while. But with the lift, the joint is starting to bind, which will then cause that to rattle like crazy while driving. You will need to replace the rear output bearing most likely. And while doing that, the rear output should be changed over to the later D20 flanged output so that you can use regular u-joints.

For the braking issue, it could be one of two things. The front shackles being at that angle can cause the springs to try and pull back (not sure how best to describe it) under braking. But what it most likely is, when you brake, the back end can rise up. And your e-brake cables that are most likely too tight now, then get tighter as the back rises. This would cause the rear brakes to oscillate between locking up, and not.

First thing I would do is loosen the spring eye bolts (not the u-bolts) while its sitting on the ground. With them all loose, work the suspension. Push up and down, rock it side to side. This is to get the suspension settled. Once that is done, then you can retighten them.
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Yeller
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Yeller »

As usual Stuka hit the spots to check first.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by will e »

The other truth (in my opinion and experience) is a 4 inch lift basically extends the drive shafts almost as much as they can extend. Stuka is right on but check the drive shafts too.
Last edited by will e on Sun May 22, 2022 6:47 am, edited 1 time in total.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by SJTD »

The ball/trunnion combines the u-joint and slip yoke functions so a new driveshaft is required too. But it was too short anyhoo as Will says.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by kjandb »

Stuka wrote: Sat May 21, 2022 5:25 pm My first question is did you leave the spring bolts loose until it was on the ground on its own weight?

If you torque it while there is no weight on the suspension, you will basically cause it to give you way more lift than you should have. Your front spring hangers should only be that far back if the suspension is drooped. Not if it has weight on it. Now, if you DID leave everything loose until it was on the ground, it looks like those springs just have way more than 4" of lift. Thats much closer to 6" as it sits now. Which is has a good chance of causing u-joint angle issues. Though the rear would have better angles with a flanged rear output (see comments below).
Yes, let it down before tightening anything and the shackles were nearly inverted, if that makes sense. Had to force them to straighten up. Since then I've loosed them, jumped up and down on all 4 corners and even drove it a bit to flex it, and then tightened them back up to spec. Here's the gain measured from bottom of fender. Old springs looked to be originals but were still in decent condition and far from flat:

Image
Stuka wrote: Sat May 21, 2022 5:25 pm Next, your wagoneer has what is called a ball and trunnion joint on the back of the transfercase. These do not handle lifts well at all. The rear output bearing has probably been bad for a while. But with the lift, the joint is starting to bind, which will then cause that to rattle like crazy while driving. You will need to replace the rear output bearing most likely. And while doing that, the rear output should be changed over to the later D20 flanged output so that you can use regular u-joints
Thanks, I'll pull it out and see what I'm dealing with. Is the flanged output the typical impossible-to-find fsj part or something my local shop can order? Have a few wagoneers at the local junkyard if it's something that later year models switched to?
Stuka wrote: Sat May 21, 2022 5:25 pm For the braking issue, it could be one of two things. The front shackles being at that angle can cause the springs to try and pull back (not sure how best to describe it) under braking. But what it most likely is, when you brake, the back end can rise up. And your e-brake cables that are most likely too tight now, then get tighter as the back rises. This would cause the rear brakes to oscillate between locking up, and not.
In one of the pics above you can see the e-brake cable is very loose since it no longer fit in the bracket. Plus it hasn't worked since I've owned it. It's so loose I don't think it would cause it but I'll probably just remove the entire cable to eliminate it as a possibility. I'm assuming that's something I can easily remove - do I need to plug the hole once it's gone?

Thanks for all your help - I'll keep playing and report back.
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Stuka
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Stuka »

kjandb wrote: Sun May 22, 2022 3:49 pm
Yes, let it down before tightening anything and the shackles were nearly inverted, if that makes sense. Had to force them to straighten up. Since then I've loosed them, jumped up and down on all 4 corners and even drove it a bit to flex it, and then tightened them back up to spec. Here's the gain measured from bottom of fender. Old springs looked to be originals but were still in decent condition and far from flat:

Image
Its possible those front springs will settle more to give a better angle on the shackle, but it almost seems like the springs are on the short side (length wise).
kjandb wrote: Sun May 22, 2022 3:49 pm Thanks, I'll pull it out and see what I'm dealing with. Is the flanged output the typical impossible-to-find fsj part or something my local shop can order? Have a few wagoneers at the local junkyard if it's something that later year models switched to?
Its a pretty common part. CJ's and FSJ's both used the D20. As far as I know, the u-joint flange will bolt up to the flange on the back of your t-case. A lot of Dana 20's use a yoke on the rear output. I know my '75 used the same flange that it appears you had, with a yoke that bolted onto it. It will be something similar to this, you would need to see if the flange mounting holes line up: https://www.summitracing.com/parts/sdh- ... QEQAvD_BwE

Also, you will need a modified driveshaft at a minimum. It will need to have a slip on it also.
kjandb wrote: Sun May 22, 2022 3:49 pm In one of the pics above you can see the e-brake cable is very loose since it no longer fit in the bracket. Plus it hasn't worked since I've owned it. It's so loose I don't think it would cause it but I'll probably just remove the entire cable to eliminate it as a possibility. I'm assuming that's something I can easily remove - do I need to plug the hole once it's gone?

Thanks for all your help - I'll keep playing and report back.
Closing off the hole will stop debris from getting inside, but chances are you already have holes where the drum adjustment slot is.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by kjandb »

I was able to to tighten the output shaft nut to spec (~150 ft lbs) and it got rid of all the play that I had before. But unfortunately it didn't fix my issue and still has the rumble and braking issue (might even be worse now). I decided to check the t-case fluid (blue arrow) and red transmission fluid came pouring out. Not dribbling over the edge but a steady heavy flow that I capped off before it made a mess of my garage. Is that normal? I expected to see gear oil, not red transmission fluid.

According to my TSM it takes GL-4 SAE-80.

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Stuka
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Stuka »

There should *NOT* be ATF in a gear driven t-case like the D20. ATF is common used in newer chain driven cases.

I still think the grumbling is the ball and trunnion joint. But you should definitely fill up the D20 with the correct gear oil.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Yeller »

If it is over flowing the seal has failed on the input shaft allowing transmission fluid to fill the tcase.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by sonoraed »

Been a while since I lifted my J10 but had to replace drive shafts front and rear, looks like rear shaft is extended all the way,also had to deal is driveshaft angles Tom Woods website has much info on this subject, lastly uou need a dropped pitman arm.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by devildog80 »

Or at least flip the tie rod at the tire, from bottom mount to top mount, so it is closer to level.
sonoraed wrote: Tue Jun 14, 2022 7:32 am Been a while since I lifted my J10 but had to replace drive shafts front and rear, looks like rear shaft is extended all the way,also had to deal is driveshaft angles Tom Woods website has much info on this subject, lastly uou need a dropped pitman arm.
'81 CJ5 Base, 258 I6, MC2100, T176 4 spd, 300 TC, D30 Front NT, 3.31, 2-Piece AMC 20 rear NT, 3.31, 4" high arc spring lift
'84 Grand Wagoneer, 401 V8 (.030 over), MC2150 HA Comp, 727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT - WT 3.31, 4" high arc spring lift
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Stuka »

devildog80 wrote: Tue Jun 14, 2022 8:48 am Or at least flip the tie rod at the tire, from bottom mount to top mount, so it is closer to level.
The TRE's are tapered, you can't just flip it.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Stuka »

Yeller wrote: Tue Jun 14, 2022 4:59 am If it is over flowing the seal has failed on the input shaft allowing transmission fluid to fill the tcase.
I think he meant it was pouring out of the filler hole when removed the plug.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by kjandb »

I think he meant it was pouring out of the filler hole when removed the plug.
Right, red fluid pouring out of the t-case filler hole. But I think he's right, I found a few other posts where the seal between the TH400 and D20 is busted and allowing ATF to enter the t-case. Guess I'll be pulling it out and taking a look. Who knows how long it's been broken - I'm guessing this isn't good for the t-case?
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by devildog80 »

Oh Geez.....nothing is easy as that :/
Stuka wrote: Tue Jun 14, 2022 6:10 pm
devildog80 wrote: Tue Jun 14, 2022 8:48 am Or at least flip the tie rod at the tire, from bottom mount to top mount, so it is closer to level.
The TRE's are tapered, you can't just flip it.
'81 CJ5 Base, 258 I6, MC2100, T176 4 spd, 300 TC, D30 Front NT, 3.31, 2-Piece AMC 20 rear NT, 3.31, 4" high arc spring lift
'84 Grand Wagoneer, 401 V8 (.030 over), MC2150 HA Comp, 727 auto, Selec-trac NP229, AMC 20 REAR - D44 FRONT - WT 3.31, 4" high arc spring lift
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Yeller »

kjandb wrote: Tue Jun 14, 2022 6:31 pm
I think he meant it was pouring out of the filler hole when removed the plug.
Right, red fluid pouring out of the t-case filler hole. But I think he's right, I found a few other posts where the seal between the TH400 and D20 is busted and allowing ATF to enter the t-case. Guess I'll be pulling it out and taking a look. Who knows how long it's been broken - I'm guessing this isn't good for the t-case?
It’s not as bad as you would think, especially since it was way over full. If it has issues it won’t be due to the ATF in the tcase.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

Post by Stuka »

Yeller wrote: Tue Jun 14, 2022 4:59 am If it is over flowing the seal has failed on the input shaft allowing transmission fluid to fill the tcase.
I just realized I misread what you said. In my head I was thinking output shaft since he stated he tightened it up just above.

It guess when he drains it he will see. When it sits, the gear oil and ATF will separate, so it should drain the gear oil, and then change colors to ATF.
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Re: Post 4" Lift Woes - Violent Braking & Rumbling

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